I have a Glow worm 30cxi and it keeps cutting out, the fault has been going on
for some time, but we can usually restart it by switching it off, leaving it
for a few minutes and switching back on. However it is now not responding to
this!
Is the fault common to this boiler, what are the likely causes and finally how
much am I likely to be looking at for its repair?
Thanks

"John" wrote in message
...
I have a Glow worm 30cxi and it keeps cutting out, the fault has been
going on
for some time, but we can usually restart it by switching it off, leaving
it
for a few minutes and switching back on. However it is now not responding
to
this!
Is the fault common to this boiler, what are the likely causes and finally
how
much am I likely to be looking at for its repair?
Thanks

Look through the fault finding guide in the instructions. They are
downloadable from their web site. It could be going out on overheat. Is it
in the guarantee period? They are guaranteed for 2 years.

In message , John
writes
I have a Glow worm 30cxi and it keeps cutting out, the fault has been going on
for some time, but we can usually restart it by switching it off, leaving it
for a few minutes and switching back on. However it is now not responding to
this!
Is the fault common to this boiler, what are the likely causes and finally how
much am I likely to be looking at for its repair?
Thanks

Do you live in a hard water area?

The heat exchanger might be getting furred up and overheating because of
the reduced flow

or several other reasons

--
geoff

I also have a 30cxi, installed Jan 2005. In Aug 2005 the water inlet valve was replaced after a fault was found causing it to 'stick' in the closed position - so I could not re-pressurise after a loss (bleeding rads etc.)
The valve was again replaced in Jan 2006 for same reason.
A design mod. on the water inlet valve (by Glow Worm) necessitated a further change in Mar 06 and thereafter I had difficulty re-pressuring above 0.7 bar.
The boiler is designed to stop operating should pressure drop to 0.6 bar or lower, and when very cold, at night, this pressure can fall that low.
I have now had an external water filling loop installed and can pressurise to 1.0 bar cold. The natural expansion when hot causes op. pressure to be about 1.6 bar.

I'm of the opinion that the new, replacement water inlet valve assembly, having two non-return valves and an airbreak is having a reducing effect upon the pressure.

Finally, after much "debate" Glow Worm have covered the installation costs of the external filling loop and the original installer has today installed said item.

Note, it is rumoured that water supply companies are reducing their mains water pressure to reduce leakage from mains pipes. This could, with the internal filling loop resistance cause a drop in the water pressure available when pressuring from cold. That said, United Utils tested pressure at ground floor level at 2.2 bar, and as boiler is 3 metres higher one would expect 0.3 bar pressure loss. So, 1.9 available should pressureise the 30cxi to 1.5-1.6 allowing for a nominal amount of resistance resulting from the internal filling loop and now, with the external, there should be 1.9 available to it.

Still only able to pressurise to 1.0 bar cold though.

On Mon, 20 Mar 2006 13:10:55 +0000 MikeCunliffe wrote :
So, 1.9 available
should pressureise the 30cxi to 1.5-1.6 allowing for a nominal amount
of resistance resulting from the internal filling loop and now, with
the external, there should be 1.9 available to it.

The resistance of the filling loop is immaterial. You should be able to
pressurise the system to the static pressure in your water main (adjusted
for storey height). A high resistance filling loop will just make this
process a bit slower.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.12 released 8 Dec 2005]

Thanks Tony,
that seems reasonable. With a tested pressure of 2.2 bar (measured by United Utils) 10ft below the boiler location, and 1.2bar at the boiler (measured by Glow Worm regional service manager) I fail to understand why I'm struggling to pressurise much above 1.0 bar and why there's such a pressure loss for a 10ft height difference.

Mike